This topic made me register. So hi to everyone from Prague, Czechia :-)
I used to listen quite a lot to Finnish music during my folk metal phase a couple of years ago. Finntroll, Korpiklaani, Ensiferum, Moonsorrow to name a few. And not just folkmetal or metal in general. Well, Kotoroiwa, if you like Nightwish, how about The Gathering? Their album Mandylion charmed me a long time ago. They are Dutch, however, so I¨ll proceed to Czech music. You probably know Master's Hammer. They used to be quite influential back in the early 90s. But do you know about their comeback? And do you know that they have a song about Pentti Linkola (may he rest in peace): https://www.youtube.com/watch?v=o2kBQPwZmzM The trouble with Master's Hammer is of course their stubborn use of Czech. But man, are those lyrics good. Franta Štorm is in his professional life a typographer (an internationally famous one) and for some time he was teaching at a university. His playful approach to language with lots of archaisms taken from books in which he studies the scripts is pure delight.
Speaking of unusual metal. Workoholic Lord Morbivod and his many bands: Umbrtka (work, dirt, industry, greyness, more dirt and more work; and work); Stíny plamenů (sewer system in West-Bohemian Plzeň and the mythological beings inhabiting it), War for War (war, mining), Trollech (trolls, gnomes, folk tales) and others. Research for yourself, the man is insanely prolific.
What else? Silent Stream of Godless Elegy comes to mind. Not that all albums are good (or to may taste at least) but Relic Dances is worth a try. A fine fusion of Moravian folklore music and metal.
You do have Apocalyptica over there, don't you? Well, we have Tara Fuki. Not metal, but they do play cellos and, curiously, they sing in Polish, not in Czech.
And if you like your dose of classical music from time to time, try to find anything sung by the Armenian soprano Lusine Zakaryan. She was a goddess and no less.
